Sharks Are Too Hot, Scientists Warn
Scientists have noticed that sharks are moving away from coral reefs because they are becoming too hot for them. They are keystone predators whose absence could threaten ecosystems that are already struggling.
Recent studies show that sharks are leaving coral reefs because of rising ocean temperatures. This could threaten not only the ecosystems themselves, deprived of important predators. It is also dangerous for the species itself, which is already threatened with extinction.
Shark Migration Research
The conclusion that the species is migrating is based on a study of more than 120 grey sharks living on the remote Chagos Archipelago in the Indian Ocean, which the researchers conducted from 2013 to 2020. The sharks fled the reefs especially during periods of significant temperature increases, such as in 2015-2016. They spent less and less time there and returned later and later. After 2016, it took them as long as 16 months to return.
It was also noticed that sharks chose the healthiest and most resistant coral reefs. Mainly those with a large population of birds, which helped fertilize them. Scientists emphasized that the increasing protection of reefs from the human factor allows sharks to remain in their natural habitats. However, the most difficult thing is to protect them from the heat.
Sharks are disappearing from hot waters
Sharks are cold-blooded, so their body temperature is linked to the temperature of the water. “If it gets too hot, they’ll need to move out,” said Dr David Jacoby, a lecturer at Lancaster University and leader of the research project.
“We think many of them are moving to deeper, colder waters, which is worrying. Some sharks are disappearing from reefs completely for long periods of time,” he added. “Reef sharks are now absent from almost 20 percent of coral reefs globally,” he warned.
Tropical coral reefs are incredible, incredibly biodiverse ecosystems that support a quarter of all ocean fish. They are becoming increasingly damaged by warming oceans, too many fish and pollution. The vast majority of reefs could be lost if global temperatures rise by 2 degrees Celsius.
